The structure of a photodetector for low luminous intensities to be processed is described, in which the photo sensitive element (photocell), a transimpedance amplifier and corresponding evaluation electronic are commonly integrated in monolithic manner, wherein a vertical arrangement of the photo sensitive element and the electronic circuitry is suggested. This offers the advantage of increasing the sensitivity of the photodetector and of saving chip area (single chip solution). When mounting the photodetector cost savings may be achieved, since the chip package may be designed smaller and less complex.